A conventionally known optical disk having a 3D moving picture stored thereon is as shown in FIG. 10. An optical disk 201 has a picture for the right eye (right-eye picture) stored in even fields 204, 204a and 204b and a picture for the left eye (left-eye picture) stored in odd fields 203, 203a and 203b. The right-eye picture and the left-eye picture are recorded alternately. When the data stored on the optical disk 201 is reproduced by an existing optical disk reproduction apparatus 205 shown in FIG. 11, a right-eye picture and a left-eye picture appear on a TV screen 206 alternately every 1/60 second. The naked eye recognizes only a picture in which the right-eye picture and the left-eye picture are overlapped. With 3D spectacles 207, in which a shutter for the right-eye picture and a shutter for the left-eye picture are switched over every 1/60 second, a 3D picture is recognized. As shown in FIG. 12, a right-eye picture and a left-eye picture are each encoded alternately in every other field as an interlace signal in 1 GOP of an MPEG signal.
For high definition pictures, progressive systems referred to as 525P and 720P have been studied.
A first problem of the conventional art will be described. When data in a conventional 3D optical disk is reproduced by an ordinary, conventional 2D reproduction apparatus, even a non-3D picture, i.e., even a 2D picture is not output. Data in the 3D optical disk is only reproduced by a reproduction apparatus connected to a 3D display. Accordingly, it is required to create two types of optical disks, i.e., a 3D optical disk and a 2D optical disk for the same contents. The same is true with the high definition picture. In other words, the conventional 3D and high definition optical disks are not compatible with ordinary optical disks. A first objective of the present invention is to provide a 3D or high definition optical disk which is compatible with ordinary optical disks, and a reproduction system for the 3D or high definition optical disk.
The term “compatibility” is clearly defined as similar to the compatibility between monaural records and stereo records discussed in the past. In other words, data in a novel 3D or high resolution disk according to the present invention is output as a “monaural” vision, i.e., as a 2D picture or an ordinary resolution picture by an existing reproduction apparatus developed for DVDs or the like, and is reproduced as a “stereo” vision, i.e., a 3D picture or a high resolution picture by the novel reproduction apparatus according to the present invention.
A second problem of the conventional art concerns a synchronization system. According to a conventional synchronization system, decoding starts when decoding conditions for each compressed video signal are provided. The conventional synchronization system has problems in that, for example, when the data becomes out of synchronization for some reason during reproduction, compensation is not performed; and that audio data is not synchronized.
A second objective of the present invention is to provide a reproduction apparatus for reproducing a plurality of compressed video signals or a plurality of compressed audio signals in synchronization with one another and performing compensation when the data becomes out of synchronization during reproduction.